Carbohydrates Facts Explain Away Myths

August 27, 1987|By Dr. Jean Mayer and Jeanne Goldberg, R.D.

The long-held myth that carbohydrates are inferior food should have been laid to rest long ago. But the myth is still alive and kicking. Today we give you a chance to sort out the facts and fantasies of carbohydrates by posing some questions of our own:

1. What are carbohydrates?

2. What is the difference between simple sugars and complex carbohydrates?

3. All carbohydrates must be broken down to one simple compound before they are burned for energy. What is that compound called?

4. What percentage of your day`s calories should come from carbohydrates? 5. Fruits and vegetables provide generous amounts of many vitamins and minerals. They, alone, provide adequate amounts of one vitamin. Which one is it?

6. In refining flours, vitamins and minerals are removed, and then put back in the enrichment process. Are these flours nutritionally equal to the original whole grains?

7. Increased amounts of carbohydrates may be fine for the general population, but diabetics are still advised to limit their intakes. True or false?

8. Is there any nutritional advantage to using honey or brown sugar in place of white sugar?

9. Animals, including humans, have limited stores of one carbohydrate. What is that carbohydrate called?

10. Of all the energy nutrients, which one provides the most calories:

carbohydrates, protein, fat or alcohol?

Now for the answers:

1. Simply put, carbohydrates are sugars and starches.

2. The major difference between simple sugars and complex carbohydrates is that the sugars contain one or at most two simple molecules linked together, while starches are much larger units. At one extreme are such sugars as glucose, or blood sugar, and fructose, or fruit sugar. They are made up of just a single molecule. At the other extreme are starches and cellulose, made up of hundreds of units of glucose chemically linked together.

3. In order to be burned for energy, all carbohydrates must be converted to glucose. Glucose is the only fuel the brain can use as a source of energy. 4. It is currently recommended that 55 to 60 percent of the day`s calories should come from carbohydrates.

5. The only foods which naturally provide vitamin C are fruits and vegetables. Liver, even after cooking, contains appreciable amounts, but most people eat it too infrequently for it to be an important source of that nutrient.

While dairy foods are important sources of vitamin A, carotenes, which the body converts to vitamin A, are a major contributor of that nutrient, too. 6. In general, several B vitamins and iron are added back in the enrichment process. But many vitamins, including other B vitamins, vitamin E and trace minerals, which are discarded along with the bran and germ, are not restored.

7. That is untrue. In recent years it has been recognized that there are several reasons why individuals with diabetes, who are at increased risk of heart disease, are well-advised to consume more carbohydrates and less fat. Beyond that, increased emphasis on foods rich in water-soluble fibers, among them legumes, roots, tubers and raw fruits and vegetables, seems to help normalize blood glucose and blood-fat levels.

8. No matter how persistent the claims, there is no significant difference among these sweeteners. They are calorically equal, and provide nothing but calories.

9. Glycogen. But with few exceptions, among them liver, clams and oysters (hardly staples in most diets), there is little glycogen left by the time you eat meat, fish or poultry.

10. At 4 calories per gram, carbohydrates and proteins calorically are the least dense of the energy nutrients, followed by alcohol, at 7 calories per gram. Fats top the list at 9 calories a gram. That explains why, for example, a whole cup of cooked spaghetti contains 170 calories, 10 fewer than just 2 ounces of steak.